ABSTRACT: Deception arises in various contexts. At times, a monopolist’s deception, while immoral, may not (or only remotely) impair competition. This article discusses deception, its potential anticompetitive effects, and the legal institutions to deter and punish deception. This article next evaluates the U.S. courts’ varying legal standards for evaluating a monopolist’s deception under the Sherman Act, and proposes a “quick-look” legal standard for evaluating such conduct.